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Optimizing Immunotherapy Combined With Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

A Prospective, Multicenter, Randomized Clinical Trial of Optimizing Immunotherapy Combined With Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer (STELLARIII)

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07040098
Acronym
STELLARIII
Enrollment
228
Registered
2025-06-26
Start date
2025-06-01
Completion date
2030-06-30
Last updated
2025-06-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Locally Advanced Rectal Cancer (LARC)

Keywords

Locally advanced rectal cancer, TNT, Immunotherapy, CR rate

Brief summary

This study explores the key clinical issues in the field of neoadjuvant therapy for locally advanced rectal cancer. There are three core problems with the currently recommended total neoadjuvant therapy (TNT) in the guidelines: the lack of evidence-based consensus on the timing of radiotherapy and chemotherapy, the undefined number of chemotherapy cycles, and the uncertainty in the selection of the precise radiotherapy mode. In recent years, the combination of immune checkpoint inhibitors (ICIs) with the PD-1/PD-L1 inhibitors as the core and the TNT regimen has shown a trend of further enhancing tumor regression, providing a possibility for the organ function preservation of rectal cancer. However, existing clinical studies exhibit a high degree of heterogeneity in treatment strategies. In particular, there is a lack of high-quality evidence-based medical evidence in core aspects such as the timing of ICIs intervention and the combination of treatment regimens. This study is designed as a prospective, multicenter, randomized controlled phase II study. The pick the winner strategy for screening the optimal regimen is adopted to evaluate the efficacy of four neoadjuvant regimens (Group SCRT-4: short-course radiotherapy → 4 cycles of chemotherapy + ICIs; Group SCRT-6: short-course radiotherapy → 6 cycles of chemotherapy + ICIs; Group LCRT-4: concurrent chemoradiotherapy → 4 cycles of chemotherapy + ICIs; Group LCRT-6: concurrent chemoradiotherapy → 6 cycles of chemotherapy + ICIs). By evaluating indicators such as the complete response rate, organ preservation rate, safety, long-term survival, as well as the anal function and quality of life of patients, treatment strategies with clinical advantages will be screened out, providing an evidence-based basis for subsequent phase III confirmatory trials.

Interventions

DRUGSintilimab

PD-1 inhibitor

RADIATIONShort-course radiotherapy

Pelvic radiation, SCRT, 5 Gy x 5 alone

RADIATIONLong-course concurrent chemoradiotherapy

Pelvic radiation, 50 Gy in 25 fractions over 5 weeks, concurrently with capecitabine (825 mg/m2, twice a day).

COMBINATION_PRODUCTCAPOX

chemotherapy regimen, Oxaliplatin 130 mg/m2 IV day 1,Capecitabine 1000 mg/m2 twice daily PO for 14 days(3 weeks per cycle)

Sponsors

Cancer Institute and Hospital, Chinese Academy of Medical Sciences
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

1. Age 18-75 years, regardless of gender; 2. Pathologically confirmed rectal adenocarcinoma with immunohistochemical results indicating pMMR (proficient mismatch repair) or genetic testing confirming MSS (microsatellite stability); 3. Staged as clinical stage II/III (cT3-T4N0 or cT2-4N+, no distant metastasis, per the 8th Edition AJCC Cancer Staging Manual, 2018) via MRI or endoscopic ultrasound, and meeting any one of the following: * cT3 with tumor inferior margin ≤ 6 cm from the anal verge; * cT3c/d with tumor inferior margin ≥ 6-12 cm from the anal verge; ③ cN2; ④ cT4; ⑤ MRF+ (mesorectal fascia involvement); ⑥ EMVI+ (extramural vascular invasion); 4. ECOG performance status 0-1; 5. Meeting basic laboratory criteria (e.g., hematologic, hepatic, and renal function); 6. No history of hypersensitivity to 5-Fu-based agents or platinum-based drugs; 7. Patients with primary rectal cancer must have received no prior surgery (excluding palliative colostomy), chemotherapy, or other antitumor therapies from diagnosis to enrollment; 8. No prior radiation to the planned radiotherapy site; 9. Signed informed consent form.

Exclusion criteria

1. Prior treatment with anti-PD-1/L1 and/or anti-CTLA-4 immunotherapy or other investigational immunotherapeutic agents; 2. History of severe autoimmune diseases, including active inflammatory bowel disease (IBD) (e.g., Crohn's disease, ulcerative colitis), rheumatoid arthritis, scleroderma, systemic lupus erythematosus, autoimmune vasculitis (e.g., granulomatosis with polyangiitis); 3. Symptomatic interstitial lung disease or active infectious/non-infectious pneumonitis; 4. Risk factors for bowel perforation, such as active diverticulitis, intra-abdominal abscess, gastrointestinal (GI) obstruction, abdominal carcinomatosis, or other known predisposing conditions; 5. History of other malignancies, except for cured non-melanoma skin cancer or cervical carcinoma in situ; 6. Active infection, heart failure, myocardial infarction within 6 months, unstable angina, or uncontrolled arrhythmia; 7. Physical examination findings or clinical laboratory abnormalities deemed by the investigator to interfere with study outcomes or increase treatment-related risks, or other uncontrolled comorbidities; 8. Pregnant or breastfeeding women; 9. Congenital or acquired immunodeficiency disorders, including HIV infection, or history of organ/stem cell transplantation; 10. Active hepatitis B (HBV-DNA ≥2000 U/mL), hepatitis C (HCV), or active tuberculosis infection; 11. Prior administration of cancer vaccines or receipt of any vaccine within 4 weeks before treatment initiation (Note: Seasonal inactivated influenza vaccines are permitted; live-attenuated intranasal vaccines are prohibited); 12. Concurrent use of immunomodulators, chemotherapy, investigational drugs, or long-term corticosteroids (≥10 mg/day prednisone equivalent); 13. Patients with psychiatric disorders, substance abuse, or social circumstances that may compromise compliance, as assessed by the investigator; 14. Hypersensitivity or contraindications to the study medications.

Design outcomes

Primary

MeasureTime frameDescription
Rate of complete response2 months after completion of neoadjuvant therapy or 10 days after surgeryThe rate of pathological complete response plus clinical complete response

Secondary

MeasureTime frameDescription
Tumor downstaging rate10 days after surgeryrate of ypT0-2N0
Rate of acute toxicities during radiation, chemotherapy ± immunotherapy1 week after completion of neoadjuvant therapyIncidence of acute toxicities during radiation, chemotherapy ± immunotherapy
Rate of surgical complications3 months after completion of surgeryClavien-Dindo Grade
Rate of OS3 years after randomizationoverall survival
Rate of DFS3 years after randomizationDisease-Free Survival
Rate of TRG grade10 days after surgeryDowrak TRG grade
Rate of DM3 years after randomizationDistant Metastasis
Organ Preservation Rate3 years after randomizationThe organ preservation rate is defined as the proportion of patients who successfully retain the rectal organ and its function through effective local treatment of the primary lesion, achieved by approaches such as a watch-and-wait (W&W) strategy or local excision. Successful organ preservation is determined if the following criteria are met: 1. Undergoing the W&W approach without local regrowth; 2. Undergoing local excision with negative resection margins and no local recurrence; 3. Avoidance of total mesorectal excision (TME) surgery with preservation of functional rectal reflex pathways; 4. No definitive evidence of residual local tumor; 5. Absence of a permanent stoma or unclosed temporary stoma.
Quality of life (QoL) in cancer patientsbaseline, 10 days after completion of neoadjuvant therapy, 10 days after surgery, 3 months after randomization, 6 months after randomization, 1 year after randomization, 2 years after randomization, 3 years after randomizationQuality of life in cancer patients will be evaluated using the European Organisation for Treatment and Research of Cancer (EORTC) Quality of Life Questionnaires QLQ-C30 . The scoring and interpretation of the QLQ-C30 scales were performed according to the EORTC guidelines. Each item is scored from 0 to 100, with higher scores indicating better functioning on the functional scales/items and more severe symptoms on the symptom scales/items.
Quality of life (QoL) in rectal cancer patientsbaseline, 10 days after completion of neoadjuvant therapy, 10 days after surgery, 3 months after randomization, 6 months after randomization, 1 year after randomization, 2 years after randomization, 3 years after randomizationQuality of life in rectal cancer patients will be evaluated using the European Organisation for Treatment and Research of Cancer (EORTC) Quality of Life Questionnaires QLQ-CR29 . The scoring and interpretation of the QLQ-CR29 scales were performed according to the EORTC guidelines. Each item is scored from 0 to 100, with higher scores indicating better functioning on the functional scales/items and more severe symptoms on the symptom scales/items.
Anal functionbaseline, 10 days after completion of neoadjuvant therapy, 10 days after surgery, 3 months after randomization, 6 months after randomization, 1 year after randomization, 2 years after randomization, 3 years after randomizationAnal function will be evaluated using the Wexner incontinence score. This scoring system consists of 5 items evaluating the frequency of gas incontinence, frequency of liquid incontinence, frequency of solid incontinence, frequency of wearing pads, and lifestyle alterations, with a score ranging from 0-4 for each question. The total score is calculated, with higher scores indicating poorer anal function.
Rate of LRR3 years after randomizationLocoregional Recurrence

Countries

China

Contacts

Primary ContactYuan Tang
tangyuan82@126.com+86-15011304945
Backup ContactXiao Qin
xiaoqin@cicams-sz.org.cn+86-18390854868

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026